Describe a conifer plant. Characteristics and distribution of conifer class plants

Conifers arose in Late Carbon (about 290 million years ago), when the climate on the planet began to be trembling. The leaves of modern conifers have a lot of features testifying to their drought resistance, i.e. possess xeromorphic signs. This may be due to the fact that most of the representatives of this class were finally formed throughout dry and relative to the cool Permian period (286 - 248 million years ago). At that time, the gradual increase in aridity probably favored this kind of structural adaptation.

Coniferous needle leaves (pine, spruce, fir, larch) or scratched (thuja, cypress), as a rule, evergreen ( schl. Larch - a secondary adaptation to a very cold climate), adapted to the economical transpiration of water and to transfer drought, including winter, when the roots cannot absorb water at low temperatures.

1) The outer surface of the chewing is very small (Mala Evaporation Square).

2) Epiderma consists of thick-walled cells to a powerful cuticle (protection against evaporation).

3) Immersed dust. The closing cells are partially decorated, and the channel is filled with resins or wax (a sharp decrease in transpiration).

4) Under the epidermary ring there is a special fabric of the hypoderma, consisting of glued fibers, which reduces evaporation and increases mechanical strength.

5) The main difference from the covered brine: there is no differentiation on the column and sponge mesophyll, all the cells are homogeneous, form foldful mesophyll.This is an adaptive compensation for a small outer surface. In mesophyll cells, the shell forms internal folds, which provides a sharp increase in the post-wing layer of the cytoplasm and the inner surface.

In cells, due to the increase in their inner surface, the number of chloroplasts increases, and at a small outer surface of the chevying, the processes of photosynthesis are also intensively, as in conventional leaves of flowering plants.

6) Double vascular fibrous beam is surrounded by an endoderma regulating the vehicles. When entering the stem double bundle merges into one, forming one sheet trail.

7) Conductive beams are surrounded by a transfusion cloth, which consists of: a) from radial tracheid (water transport), b) cells of living parenchyma (vehicles of organic substances-assimilates).

8) There are resin moves located between the mesophyll cells.

21. The classification of leaves on the shape of a sheet plate, base, top and the shape of the edge of the sheet, according to the degree of dissection. Classification of complex leaves.

22. Types of leaf housing. List. Sheet modified.

23. Flower. Flower morphology.

24. Flower value. Forms and types of flower. One-bedroom, dioval and polygamous plants. The concept of the formula and flower chart.

25. Inflorescences. Types of inflorescence.

26. Seed. Seed structure.

27. Physiology of seed and its germination.

28. Sex reproduction of plants. Types of pollination. Adaptation of plants to pollination. Fertilization of flowering plants.

29. The spread of fruits and seeds.

30. Fetus. Classification of fruits.

31. Mascable reproduction of plants.

In plants, two forms of mineral reproduction are distinguished - vegetative, based on the ability of plants to the regeneration of individual parts of the plant, and reproduction with specially formed cells - dispute.

Vegetative reproduction It is found in both unicellular and multicellular plants. For example, many single-cell algae multiply with the help of mitotic cell division into two.

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purpose : To summarize, systematize and deepen the knowledge of the vote on the example of coniferous plants of the city of Izhevsk.

Tasks:

Cognitive Wood:

Perform universal logic actions:

Perform analysis (allocation of the characteristics of the structure of gosled plants),

Choose the grounds for comparison, classify objects,

Establish analogies and causal relationships based on working with natural objects;

Arrange a logical chain of reasoning

Believe objects to known concepts on the example of a comparison of gleoty and fern.

Communicative Wood:

Draw up their thoughts in oral and written speech taking into account their educational and life speech situations;

If necessary, defend its point of view, arguing it;

Learn to confirm the arguments by the facts;

Learn critically refer to your own opinion,properly express your thoughts in speech, respect in the communication and cooperation of the partner and yourself.

Personal Wood:

Assess the importance of careful attitude towards the nature of the native land.

Equipment : photos depicting representatives of coniferous plants of Izhevsk,cards, Herbarium Coniferous Plants, Collections of cones, multimedia projector, video film.

Lesson plan.

1. Organizational moment.

2. Studying a new topic.

3. Features of coniferous plants.

4. Minds of coniferous plants of the Udmurt Republic on the example of the city of Izhevsk.

3. Actualization of the received things.

4. Homework.

During the classes.

Stage lesson	The action of the teacher	Student's action	Material and technical support
Organizing time.	Code class on lesson. Today we will explore the new systematic category of plants - voted. Do you think why this plant department got such a name?	Reply to the question, putting forward your versions of the correct answer.	Slide 1.
Studying a new topic.	Now we will see a fragment of the video film, after which you formulate a goal and task for a lesson.?	View video Fragment, Definition of the topic " general characteristics Department of gifted plants " Definition of the goal: What are the features of the structure and the value of the gifted department? Work in the table: Know I do not know I want to know	http://intellect-video.com. ) Slide 2.
Setting tasks in the lesson	Helps, advises	Sample student issues: What are the features of the structure of the representatives of this department? Value in nature and in a person's life?
Study of a new topic	Let's try to find answers to the questions set by looking through the excerpt from the video.	Browsing the following part of the video, give answers to the questions.	Video Fragment "General Characteristics Department Gamotional Plants" (or InternetResource http://intellect-video.com. ) or slides 3-8
		Determine the questions that have arisen What representatives of the department grow on the territory of Udmurtia?
		With the help of the TSOR http://school-collection.edu.ru/catalog is a diagram of reproduction of vote.	Interactive task "Drawing up a fertilization scheme gamed plants (N 137346) » Slide 9-10.
	One of the most important plants of our republic are woody plants. The main forest-forming rocks are coniferous. They are employed 55% of the entire area of \u200b\u200bforests. The first place among the conifers occupies a spruce or spruce Siberian, then the pine is ordinary. The fraction of the fir accounts for about 1% of forest area, and Sukacheva's larch is 0.1%. All listed representatives of conifers live in the capital of our republic - Izhevsk.	What are coniferous representatives meet in Izhevsk?	Slide 11-12.
Practical activity of students	Can you learn some representatives of vote on natural objects? The teacher advises.	Students are carried out educational actions on the planned plan. Perform laboratory work "variety of vote". Students define plants who are faster, argued their answer.	Plant sets with identifies cards. Attachment 1.
	Find out the features of the structure of coniferous plants, which allowed to take a dominant position in the territory of Udmurtia.	Perform laboratory work "The structure of the sheet of coniferous plants"	Microscope, microspections, slide 13 -14.
	Look at the familiar places of your favorite corners of the hometown. Name coniferous plants that you could define and name the number of photos on which this plant is shown.	Work with text and slides-presentation, define representatives of coniferous living in Izhevsk.	Slides 15- 21 presentations "The diversity of coniferous growing in Izhevsk", Appendix No. 2 "Diversity of the coniferous, growing in the territory of Izhevsk"
	Solving Crossword	Crossword solution.	Slide 22-23. "Crossword on" Coniferous Izhevsk "
	What role do these plants play in the life of the city? And what value do they play in a person's life?	1 Option: Create a cluster "Value viced in nature" 2 Option: Make a cluster "The value of voted in a person's life" Placement of clusters on the board.
	Check out the contents of the card and add the table	Work with text.	Appendix No. 3 "Class Coniferous"
Actualization of knowledge gained	Spend a comparison of the presented groups. What conclusion can be made based on the knowledge gained.	Perform a task on a comparison of plant departments and formulate the conclusion about the progress of the evolution of plants, it is evaluated.
Reflection	Did you get answers to all questions?	Sounding the content of the table, identifying the incomprehensible moments of the studied theme.
Homework	Complete the task of the proposed: Read § and give answers to questions. Create a presentation on the topic "variety of vote", "amazing nearby" (about the most interesting representatives), "The meaning of voted in nature and in a person's life" Make tasks for verification on this topic.	Students can choose a task of the proposed teacher, taking into account individual capabilities.

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Attachment 1

The purpose of the work: familiarization with the structure of the voted, determination of plants.

Equipment: live specimens or herbarium splats of spruce, Siberian, European larch fir, ordinary pine, cedar Siberian pine, identifying card.

Progress:

Using the card to determine the vote plants on the leaves, name the plant issued to you.

Card-determinant

1. The needles are located on the branches of singly .......................................... ... 2.

0. The needles are beam. . .......................................... . . 3.

2. A short, tetrahedral, tough, sharp, barbed, does not fall out for the winter ....

…………………………….…………………………………………………. spruce ordinary

0. The cooler is flat, up to 3 cm length, stupid, has two longitudinal light strips from the bottom side, it does not fall out for winter .................................................................................fir Siberian

3. Easy soft, located beams in the form of light green brushes, it falls on the winter .....................................................................european larch

0.Hweath hard, sitting by beams, does not fall on the winter ...................................... ............four

4. Found 2 in a beam, long (5-7 cm), sharp, convex on one side, Sisovo-green ...... .. .............................................................................. ......pine ordinary

0.How to 5 in a beam, long, dense dark green ...... .. ......pine cedar Siberian

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Appendix 2.

The diversity of plants of the coniferous, growing

in the territory of Izhevsk

1. The main forest-forming breed of Russia. Grows on a variety of soils, but prefers sands. Often it is planted to delay the offensive of the sands. On short shoots two cups. Corses of small size. Lightwater plant. Gives a good building and diverse wood; From the resin receive turpentine, rosin.

2. The highest tree of coniferous plants common in Russia - reaches 70 m. There are no shortened shoots. Single needle, flat. The cones are a reprehension, when ripening scattering. Forms dark-haired forests on the extensive territory of Siberia. Wood is used in paper manufacturing, valuable balm is produced from the bark.

3 Large tree with a height of up to 50 m with a characteristic pyramidal form of the crown. There is no shortened shoots. Single cupllies are usually tetrahedral. Corps leathery, hanging, large size. The tree is shadowfully. Gives valuable wood wood.

4. Lightweight wood forming light forests. Wood solid, resinous, durable. At shortened shoots - bundles of soft needles, annually on the winter is discharged. Small bumps, ripen during the year, but hold on the branches for several years. Widespread in the Urals, in Western and Eastern Siberia and the Far East.

5. High wood forming forests on the extensive territory of Eastern Siberia and the Far East. At shortened shoots - bundles of 5 chewing. Gives valuable wood and large edible seeds, called nuts, of which are produced by valuable oil.

6. The richest type of coniferous trees and shrubs. The leaves of needle or scratch uniforms, located boring on shoots. Women's cones have juicy scales, forming peculiar "berries" with seeds. They are used to prepare a sturdy drink.

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Appendix 3.

Class coniferous.

All coniferous - evergreens, less often leave (for example, larch) trees or shrubs with needles or scratching (for example, at cypress) leaves. The needy leaves (needles) are dense, leathery and tough, covered with a thick layer of cuticle. The dust is immersed in the recesses filled with wax. All of these features of the structure of the leaves provide a good adaptation of coniferous to grow in both arid and cold habitats.

Coniferous serve trunks covered with scaly bore. Developed wood and less developed bark and core are clearly visible on the cross section of the stem. Xylem coniferous by 90-95% formed by tracheids. Cone coniferous separation; Plants - more often one-bedroom, less often - digestive.

At coniferous, each needle almost completely reproduces the structure of the stem. The outer layer of Cell Cells, a peculiar "bark" is called the epidermis. From above, the cheeks are covered with wax cuticle. The epidermis follows a hypoderma, or podlochet, - thick-walled cells that protect the leaves from damage (wood would fit the hypoderma). Many coniferous hypoderma is winning. Wooden shells have a fir housing, cedar and pine.

The hypoderma is located the most important fabric needle - parenchyma, its deep folds are literally styling with green balls of chlorophyll - chloroplasts. It is in the parenchyme that photosynthesis takes place. Smolyma moves are arranged in the parenchyma (resin strokes are not all coniferous), their small cells are separated by resin. Every resin move like water pipe, Surrounded by thick-walled cells of mechanical tissue. Even closer to the center of the needle there are vascular fibrous beams surrounded by "inner skin" - mechanical endoderma cloth. On the alasty fabric - xylem - conductive water goes from the branch to the end of the chevyo. Under univent fabric - Floem - organic substances move in the opposite direction. There is also own parenchyma in the conductive beam. Sometimes she is green - working on synthesis, but more often - gluable, especially in long needles. In this case, the vascular fibrous beam serves as a rigid axis that does not allow the chevying to bend.

Ustian, through which coniferous breathe, are usually hidden deep under the endoderma, which allows you to strongly reduce water consumption in winter to evaporation, and in the summer - during drought.

In the wax shell dissolve the combustion products of automotive fuels, which is why conifers are poorly growing in the city. Conifers are capable of increasing the thickness of the cuticle, and the worse the environmental situation, the thicker the wax shell and the brighter the chevings. But when a certain limit is reached, the disintegration of the cuticle, the needles becomes dirty gray, loses his shine and falls.

Conifers - a group of seed vascular plants. Modern representatives of conifers are evergreens, less often, leaf fall trees and shrubs.

According to one of the classification systems, this group is combined into a class of coniferous or pinsida (Pinopsida) of the gymnospermae (Gymnospermae). This class is divided into two subclasses: the extinct subclass of Cordate (Cordaitidae) and a modern coniferous subclass (Pinidae or Coniferae).

On another classification system, all modern coniferous combined conifers (Coniferales) included in the CONFEROPSIDA class (Coniferopsida) class of gaming plants. Another system attributes modern coniferophyta independent department.

The Russian name "coniferous" comes from the word "needle", which designate the needy leaves of some of their representatives (for example, spruce, fir, pine). However, not all coniferous leaves are "chew". Equally not exactly the name of the "pinny", which is a translation of the second Latin name Coniferae (from the lat. Conus - a bump and Ferro - wearing), since the bumps are far from all representatives of this group.

Spread

Coniferous - plants predominantly temperate warm climate, for the existence of which, above all, sufficient moisture is necessary. Therefore, they are mainly growing in a temperate climatic belt. The northern border of the spread of wood conifers (as well as in general wood species) coincides with the isotherm of July + 10 ° C. Further promotion of the forest (including coniferous forest) to the North prevents the lack of heat and the associated presence of many years of milling with a thin soil seasonal layer Towing, which does not allow the roots of trees to receive sufficient moisture and nutrients from the soil. However, according to the valleys of rivers and streams, where due to the pepper effects of water, the layer of seasonal thawing increases, coniferous forests are moving to the north a little further. In the subtropical and tropical climate, the growth of conifers is hampered by insufficient atmospheric moistening, so they grow in these climatic belts mainly in the mountains at such heights on which the climate corresponds to the climate of the temperate climatic belt.

Fig.1. Cedar Siberian (Lat. Pinus Sibirica)

Now existing coniferous is the most numerous and most common group among modern voters. The greatest number of types and genera of conifers is found in the northern hemisphere. Some of them, for example, pines, ate, larches, fir forming extensive coniferous forests here, sometimes from one or few species. In the southern hemisphere, conifers are most abundant in the temperate regions of New Zealand, Australia and South America.

Most endemic clans of conifers (childbirth, whose distribution is limited to a very small territory) and all ancient relics of childbirth (childbirth that in this territory is a remnant of flora of past eras, their presence may be in some inconsistency with modern conditions for existence on this territory) focused along the pool Pacific, especially in Southeast and Central China, in Taiwan, in Japan, New Caledonia, Tasmania, on the Pacific Coast of North America, in South Chile, New Zealand, East Australia and New Guinea. This is due to the fact that climatic conditions in the field of the Pacific Ocean have undergone the least changes after the Mesozoic, the era, in which this group reached its maximum development. Not only the number of births, but the number of coniferous types increases towards the Pacific Ocean.

In their value, both in nature and in human life conifers occupy second place after flowering plants, far surpassing all other groups higher Plants.

History of development

Conifers appeared in the coal period (about 370 million years ago), and at that time they grew mainly in the northern hemisphere. They survived their parents of Cordate and already from a triad period (OK.235-185 million years ago) began to play a significant role in the vegetation cover of the northern hemisphere. In the Jurassic and especially chalk periods of the Mesozoic era (OK.185-66 million years ago), conifers achieved the greatest diversity and maximum distribution. At this time, most modern birth appeared, and Pine (Pinaceae), TaxaCeaEa (Taxaceae), Taxodia (Taxodiaceae) and Cupressaceae (Cupressaceae), and Cupressaceae (Araucariaceae) were concentrated in the northern hemisphere, and in the South Araucariacea (Podocariaceae) family.

In the tertiary period of the Cenozoic era (about 66-2.5 million years ago), conifers were widespread throughout the land, they were not so noticeably concentrated around the Pacific Ocean, as it is time. They then grew even in the polar areas, in the territories lying outside the border of the spread of wood vegetation (Svalbard, Western Greenland, Antarctica). Interestingly, in Antarctica coniferous grown even at the Quaternary time (2.5 million years ago and later).

The coniferous ancient all now existing groups of seed plants, including even ginkgy, which are quite reliable remnants of which are known from the Perm period (this period began 280 million years ago and lasted 45 million years). But while only one species is preserved from the ginkgo class (in essence, genuine "live fossil"), coniferous represents a prosperous group. Among the modern coniferous, the most ancient families are the family of arakariy, gummock and pine. More or less reliable remnants of representatives of these three families are already known from the deposits of the end of the Perm period (about 250 million years ago), and pine, apparently, appear somewhat earlier than two others. Ancient age is not only among families, but also some kind of birth. So, plant residues, more or less confident pine (Pinus), are known from the deposits of the Jurassic period (their age from 185 to 132 million years old), and the pollen grains of the genus Kedr (CEDRUS) - from the deposits of the end of the Perm period (their About 250 million years old). This suggests that some modern breeding of conifers existed before the Cretaceous period, i.e. Before the appearance of flowering plants.

Dimensions and lifetime

Modern representatives of coniferous - evergreen, less often decopter trees and shrubs. The sizes of conifers are very different - there are all transitions from dwarf forms to the real giants. By gigantic sizes, the first place belongs to Sequoire evergreen (Sequoia Sempervirens), attributable to the collection of taxodiev. This is the highest tree in the world. Its average height of more than 90 m, and a record - 117 m; The diameter of the trunk can reach 11 m. The thickness of the separation of the sequoia is inferior only to Mexican Bolotny Cypress (Taxodium Mucronatum), the thickness of the trunk of which can reach 16 m, and the mammoth tree (sequoiadendron Giganteum) whose mighty copies have a thickness of up to 12 m. Among dwarf conifer championship Belongs to the New Zealand Dacrydium Rykhloliste (Dacrydium Laxifolium) from the family of submarines, the height of which is less than 1 meter. This tiny coniferous with thin fluttering stems forms thickets, mainly on mountain and subalpine peatlands in areas with a wet climate.

Some types of conifers are one of the most long-lived plants in the world. Such, for example, the long-liver is Mammoth Tree, the age of some of its copies is more than 3000 years, but the record of longitudeship breaks another species, namely the North American pine (Pinus Longaeva). In Eastern Nevada, an instance of this species was found, which is determined by approximately 4,900 years, and almost five thousand years. So, during the construction of the pyramid of Heops, this plant was already quite old (he was more than 200 years).

Structure

Shoots. Most conifers have two types of shoots: unlimited growth of long shoots (auxiblasts) and limited in growing shortened shoots (brachiblasts). Branching of shoots at coniferous - monopodial. With this type of branch, the main stem (monopodies) developing from the seed has an unlimited top growth, due to which the plant grows in height. Side shoots of the first, second, etc. depart from monopodia. orders. The shoots that depart from the main trunk are located on the helix, however, they often come closer, which turn into a muve (rings of shoots around the main trunk), and no more than one such rings are formed annually. Considering the muve, you can determine the age of wood, adding to the resulting figure for 2 years, since the first 2 years of life in coniferous trees are not formed. However, this method is applicable to relatively young (up to 50 years) of plantations, in which the lower dwarfs on the trunks have not yet managed to completely delay due to the secondary growth of the trunk.

The branches of such false mutations are gradually shortened towards the upwards, which gives the tree a characteristic pyramidal form. At the same time, the side branches of the second and the following orders are arranged by bilateral symmetrically, is sometimes completely flat, which gives a tier in nature. If the Top Escape is damaged, then one of the branches of the very young flutter of the side branches can start growing up and take the role of the main one. Old trees typically formed a wide email crown, consisting not from one, and from several main branches, which is well noticeable, for example, in old pines.

As the tree agrees, in open position, its lower branches can persist, reaching almost to the ground (frightened crown), but in dense forest they usually die quickly due to lack of light. As a result, the long lower part of the barrel is broken and remains almost without harsh, which is very valued when the wood harvesting.

In most coniferous, growing in cold areas, the tip of escape is protected by tightly sitting thin scales forming a clearly pronounced kidney at the end of the growing season. Renal scales are covered with a protective layer of resin or tightly covered with thick hair. In other cases, for example, Araucaria and most cypress, renal scheels do not develop.

Stem.The anatomical structure of conifer stems is relatively monotonous. They have a fairly thin bark and massive wood cylinder, inside of which - the core, barely distinguishable in older trunks. Both in the crust and in the wood itself, many smallest moves (canals) consisting of elongated interclause spaces. Resin channels are filled with a resin, which is released by the lining cells.

Most coniferous in the trunk has clearly pronounced rings of wood growth, the formation of which is associated with a slowdown in the growth of the tree into the annual periods of winter cold or summer drought. Each ring corresponds to wood gain in one growing season. These rings are distinguishable on transverse slices of trunk, branches and roots. Best of all, they are expressed in coniferous moderate and cold latitudes. By the number of annual rings on the cutting of a trunk, spent at the height of the root of the root, it is possible to quite accurately determine the age of the tree. Moreover, on the basis of a number of signs of the structure of the rings of growth, we can make certain conclusions about the climatic conditions of the past. The study of the rings of coniferous growth (as well as wood flower) is used to dating archaeological residues and natural phenomena (such a method is called dendrochronology), as well as to study the ancient climate (dendroclimatology).

Root. The primary root in many conifers remains all his life and develops in the form of a powerful rod root, from which side roots depart. Less often, for example, some pines, the primary root will underdesert and is replaced by side. In addition to the long roots (main and side), coniferous has both short, often very branched roots, which are the main absorbent organs of the plant. Such roots may contain mikuriza - symbiosis mycelium mushroom and plant roots. Mushroom mushrooms decompose some inaccessible plants organic compounds Soil, contribute to the absorption of phosphates, nitrogen compounds and produce substances of the type of vitamins, and the substances themselves are used to be removed by them from the roots of the plant.

On the roots of conifers there are root hairs in a narrow zone of the root of the root, easily dropped when washing the root. The leaves from most coniferous and needle-needed, such leaves are called a cheese, however, more ancient birth (for example, some species of araucarium and submarine) leaves lanceal and even broad-chain. So, at the size of the greatest (Podocairus Maximus), the largest leaves reach 35 cm of length and 9 cm width.

Green coniferous leaves most often sitting, but sometimes - with a short camp. Almost always they are solid, and only some kinds of fir leaves on the top more or less lavety. Their length from 1-2 to 30-40 cm. The longest leaves among modern conifers - from North American bolotnaya pines (Pinus Palustris), the needle of which reaches 45 cm of length. With the exception of several deciduous or venodatic births (araucaria, agatis, taxodium, metausexient and kunning), the leaves of coniferous evergreen, dense, more or less hard and leathery. Location, usually spiral or regular, less often - mutual or opposite. Narrow leaves (needles) have one veil, wide - many parallel veins. In the section leaves flat, tetrahedral or rounded. In addition to green photosynthetic leaves, some conifers have brown leaf-shaped leaves.

Reproduction

The coniferous reproduction authorities are strobils - modified shortened shoots that carry special leaves - sporesophilles, on which spore-forming organs are formed - sporangies. There are men's strobils (they are called microatruts) and women's gates (megastrobials). Megastorobils are usually growing with compact assembly, they are very rarely growing alone. Megastobilov meetings and single megastrobials are called female bumps.

Multi coniferous micro-tapes grow one by one, and, very rarely, in some primitive forms of conifers, - compact assembly. Collected microatruts and single microstrobals are called male cones.

Fig.2. Men's cones (strobal) on Virgin's pine (lat. Pinus Virginiana)

Usually coniferous - monocotted plants (men's and women's cones are developing on the same tree), less often they are two-walled (women's and men's cones develop on different trees).

Men's cones are most often assembled by groups and are usually located in the sinuses of the leaves, less often on the tops of the side shoots. At the base of cones often there are scales that perform a protective role. Microspophilles are very reduced, scratched or shields. Each microspophyll is formed from 2 to 15 microsposrans. A sprinkled fabric is formed in microsposrangia, surrounded by tipetium with a layer of cells that deliver nutrient material for developing microspores. The number of microspores formed in microspore is usually very large, they are very light, which helps them spread the wind.

Male Gametofit is developing from each microsphere - sexual generation of plants, life cycle which passes with alternating sexual and most powerful generations. Almost all of the highest plants (with the exception of Mids), Gametofit is poorly developed and short-lived.

Most coniferous development of a male gametophyte begins before the microspide dispelment, i.e. Even when they are inside the microspundle. The rest of conifers (most of the tissue and cypress) development of a male gametophyte begins only after the microspores are transferred to the wind on the female bumps of the nephery.

Each female bump, as a rule, consists of a central axis on which crumbling scales are sitting, in the sinus of each of which there is a seed scales, which is a changed in the process of evolution of megastremobil. In various lines of the evolution of coniferous, the process of gradual instincting of the crumbling and seminal scales (i.e. the scratched megassers), which, in the end, leads to the formation of a simple, fusion scales, often called the fertile complex.

Fig.2. Women's cones on a fir black (lat. Picea Mariana)

On the upper side of these scratch-shaped megastobils there are sicks. The segments are megasoprangi (called the nicklouse here), surrounded by a special protective substance - the integment. In each nomalus, 3-4 potential megaps are developing from which only one is capable of development. Inside Megasprangia as a result of multiple division from the functioning megapar, a female gamethophyte is developing, called endosperm.

With the help of air bags, pollen from male cones is transferred to the nephelters. There is pollination and scales of the female cones are closed. Male Gametofit continues its development on megasoprangia. After a certain period of time, after pollination, the process of fertilization begins, which usually occurs during the same season. This period of time is unusually large in the species of pine, which has been from 12 to 14 months from the pollination and fertilization. After fertilization, the zygota is formed (the cell formed by the merger of the male and female sex cells) is formed, from which immediate germ (prerepress), and then a real embryo, first begins to develop. The development of the embryo occurs due to the spare substances of the endosperma.

The formated germ consists of a root, a stalk, several cotyledons (germinal leaves) and kids. The germ is surrounded by endosperm, which is used in germination. The integument forms a solid seed peel. The segments firmly grieves the seed scales, from the fabric of which the wonder film is formed, which contributes to the spread of seeds by the wind. Thus, the ripe seed contains the germs of sporophyte, equipped with spare stubs and protected skin. Sporophyte is an affordable generation of plants, the life cycle of which passes with alternating sexual and forgenous generations. All higher plants (with the exception of mossoid) are represented by sporophytes.

Coniferous seeds are very much varied in size, shape and paint. The peel of the seed can be rustic, leathery or webbed. Seeds adapted to propagate wind are equipped with one large walled appendwatch or 2-3 small wings. Animal seeds often have juicy and brightly colored covers.

There is quite a long time between pollinating and ripening seeds. For example, at Pinus Sylvestris), the ripening of seed comes in autumn, for the second year after pollination. The cones reach the length of 4-6 cm by this time, their scales are decorated and become gray from the green. The next winter bumps down, the scales diverge and the seeds are hurt. Separating from the parent plant, the seed can be at rest for a long time and only with the onset of favorable conditions is touched into growth.



Since 1950, the systematics at the suggestion of the Dutch Botany A. Pulle instead of the previous order of connecting (confefales) combine modern coniferous in five orders of magnitude: araucaria (araucariales), pine (PINALES), cypress (Cupressales), podocarpales and texales (Taxales).

Representatives of the order of pine, combined into one family of pine, which includes 11 genera and 250 species, are the main forest-formers in Europe, Asia and North America. They form clean and mixed plantings of the light-dual and darkening taiga of the northern hemisphere. Pine are the main forest formulator breeds of our country. They occupy large areas taiga zone Eurasia, constituting the basis of the Lescage base of our country (see :). In the forests of the North Posnovy, they take the dominant position and make up about 90% of the entire forest-plated area. They have a huge water protection and protective value.

The coniferous forests of the USSR have a significant impact on the climate of the northern hemisphere of the planet and occupy a high proportion in the economy of our country. In coniferous forests, a huge mass of organic matter has been accumulated, which is a valuable source of wood, gils, fats and many other essential plant products.

Fig. 3. / - Ginkgo two-suling; II - TIS Berry: 1 - Escape with leaves and male gates; 2 - Escape with leaves and seeds; 3 - seed; 4 - seed in context; 5 - leaves; B - sheet with one vascular bundle

The order of cypressive includes two families: cypress (Cupressaceae) and Taxodia (Taxodiaceae). The cypress family combines 19 genera and 130 species growing in the southern and northern hemispheres. The Taxodius family combines 10 genera and 14 species, of which 5 are monotype. Among them are Evergreen Sequoia (Sequoia Sempervirens End!.), Sequoyadron Giganteum Lindl. Ocean.

The group of "live fossil" includes 5 clans and 20 types of Taxaceae Lindl family (Taxaceae Lindl), which are preserved in Southern Europe, Crimea, in the Caucasus, DVK, forming clean and mixed forest formations. The second family of tossess planting material - Gulp art includes two kinds and 6 species growing only in Asia (India, China, South Korea Both Japan), in mixed forests, in places rich in precipitation.

Representatives of the orders of araukarium and sub-circuit grow in the southern hemisphere. The Araucaria family is represented by Emerctual (the highest) trees of the tropical forests of South America and Australia, being forest formers on blurred mountain soils. The araucarium family includes 2 kinds and 32 types. The family of submarines includes 9 clans and 140 species of Forestrymen Australia, South America, Africa and Asia. Paleontological studies have shown that some modern representatives of coniferous existed before the Cretaceous period, that is, before the appearance of flowering plants.

Among modern coniferous, the most ancient families are arakariy, gardens and pine. For a long-term evolution, they have undergone significant changes. However, modern conifers are distinguished by a noticeable evolutionary stability of morphological structures compared to flowering plants characterized by diversity. The preservation of the competitiveness and stability of conifers in the struggle for existence contributes to the characteristic features and properties that have arisen in the process of long-term adaptive evolution.

2.2. Features of the structure of the vegetative organs of coniferous breeds

Conifers are slim high and durable forest-in-house trees that are included in the first tier of forest vegetation. The durability of conifers (from 300 to 2000 - 3000 years) is determined by the features of the structure of the trunks, differing from other voted more developed wood and less developed bark and core. Durability and Emergenity define the main century, forest-like, conifer function.

Wood conifers by 90 - 95% by volume consists of tracheid, whose length of different species It vary greatly (from 0.5 to 11 mm), and the number of bounded ports from 30 to 50 pcs., which are focused on the ends of the tracheide, where the intensity of the accommodation current is the greatest. Tracheids with rounded focused pores turned out to be sufficiently perfect water-conductive elements that simultaneously perform the reference function. The emergence in the process of evolution of a special thickening of a closing film of the bordered pore, known as Torus, was a very useful functional improvement of the tracheide. Electron microscopic studies have shown that the torus is a smooth thin plate suspended on thin threads, between which there is no refill. This makes it possible to move the fluid from the tracheide in the tracheide even at closed pores.

In the wood of coniferous, very few parenchyma, and the tees and araucaries it is completely absent. The core rays are narrow, single-row or double row (less often - wider), from 1 to 60 cells in height. Rays of conifers consist only of parenchymal cells with one or two edge rows of radiation tracheid located crosswise. Most coniferous in the trunk has clearly pronounced rings of wood growth, caused by the seasonal periodicity of Cambia's activity related to the change of seasons. Sevective rings are better drawn at coniferous moderate and cold latitudes. Studying the structure of the growth rings is the main method of section of dendrology - dendoclimatology.

In the wood and the crust of modern coniferous many smallest moves. They have the form of long narrow channels filled with essential oils, resin and balsams separated by the lining cells. Most coniferous resin moves are missing and are formed only in response to bringing the trunk. However, the arakarium resin moves are not formed even in response to damage to the stems. The resin is concentrated in tracheids, which are bounding core rays. Only for representatives of the family, pine are characterized by constant, normal (not traumatic) resin moves in secondary wood.

The ability of conifers to allocate the province is their most important biological feature. The volume of consumption and scope of application of its processing (rosin and terrent oils) is steadily expanding, despite the intensive development of the production of synthetic means and materials. The process of producing gils for terient production, which ranked the name of the line, is based on the use of the wound reaction of conifers. It turns out that the presence of normal resin moves does not lower, but by contrast, increases the response of the Cambia of such conifers for reservation.

The leaves of conifers have in most cases a pronounced xeromorphic structure. They are usually covered with a thick layer of cuticles with small epidermal cells with highly thickened walls. Stitza are immersed in recess.

Branching in coniferous monopodial. Along with the elongated shoots (auxiblasts), not limited in growth, a number of conifers have limited in growing shortened shoots (brachiblasts). Most coniferous, growing in temperate and cold regions, the top of the shoots is protected by tightly sitting thin scales forming at the end of the vegetative kidney season.

2.3. Characteristics of conifer generative organs (Fig. 4)

Coniferous, diverse, single-dollar, less often domestic plants (see :). Microstruck, which is often called the "male cooler", consists of a shortened axis, on which highly reduced microsurophylls with microspores are located. The location of microsurovophilles in most coniferous spiral (next), but in cypress microsurophylls there are always opposite or mutton. The form of coniferous microspilles is very different.

In systematics of coniferous, exceptional interest is the structure of female strobils, which were called macro or megastrobyls.

The decrease in the number of macrosturbs is a common direction of the evolution of coniferous. In tees, as a result of the far-seated reduction of the number of macroscipes, the formation of single, single-bedded macroscipes occurs. The evolution of most conifers went towards an increase in the compactness of the collection of macrosturbs, a decrease in the number of parts played a minor role. As a result, compact strobes occurred - the type of pine cones, spruce, araucaria and other conifers. The bumps during the flowering period agreed to call megastrobyls. Megastremobil (macrostrukil) consists of a central axis on which crumbling scales are sitting, in the sinus of each of which is the so-called "seed scales". They are called "seeds" because on their upper side they carry the sicks, or seeds. The question of the origin of the seed scales for a long time served as the subject of large disagreements and numerous studies that confirmed the hypothesis R. Florin, known as the title, the theory of "stubborn brachiblast". It has been established that in various lines of the evolution of conifers there is a parallel process of gradually sharpness of the crumbling and seed scales (more precisely, the scratched megastrobyl), which, in the end, leads to the formation of a "simple" fusion "scales", which is often referred to as the "fertile complex".

Most representatives of the family of pine pollen, or microscpons, has a bean shape with two protrusions, or air bags ( planting material: pine, spruce, fir). For most types of tsi, a typical spherical pollen with one slotting air bag. The larch and pseudoots are no pollen bags, and pollen has a spherical shape.

Most coniferous development of a male gametophyte begins before the microspide disperse, that is, when they are inside the microsphang. But the tees and most cypress (juniper, cypressions, etc.) microspores are distributed in a single-core state and, in such images, are not yet "pollen grains" in the strict sense of the word. In the latter case, the development of a male gamemarketophyte begins only after the microspores are transferred to the wind on the seed.

2.4. Pollination and fertilization at coniferous

Fig. 4. The structure of male and female strobils of pine (I), spruce (II), larch (III) and fir (GU): 1 - Men's gates; 2 - strob axis; 3 - stamens; 4 - seeds; 5 - a crooked flake; b - pollen

Shopping, i.e., the transfer of pollen into the seedness of the air movement occurs differently. The most famous type of pollination is one that is characteristic of a pine having pollen with two air bags. Seed pine scales during flowering period are somewhat spread out, which indicates that its facing seeds are ready for pollen acceptance. The abundant amount of pollen delivered by the wind falls into the intervals between the seed scales and is delayed by the so-called fervent expansions of the edge of the micropower (powder). Pine these extensions are relatively thin, and the eating it is wider and more succulent. By this time (and sometimes before), the micropyle begins to distinguish the so-called pollinating fluid, protruding on its top in the form of a drop ("pollinating drop"). Pollen grains are easily wetted by pollinating liquid and quickly immerse themselves into it. Shortly after such a dive occurs, fast fluid readsorption occurs, ending in 10 minutes or even earlier. As a result, pollen grain is as if sucking inside and reaches the tops of megasoprangia (nomalus), where he germinates. Thanks to air bags playing the role of peculiar swimming devices, pollen grain as it moves up the microdiolar channel all the time remains the oriented distal pole down towards the pollen, formed by the edges of the nicknole. In this position, the pollen grain will easily germinate and forms a pollen tube. After pollination, seed scales come closer and remain tight pressed to each other until seed ripening.

The disappearance of air bags in pollen pollen and pseudootsuchi is due to the lack of pollinating fluid, for swimming in which they serve. It should be noted, however, it should be noted that the fir and cedar has a pollinator not stand out, but pollen grains are still equipped with air bags, although the cedar has a tendency to their reduction. In the fir, the microfilar area turns into a slanting fighter funnel, causing pollen. But pollen grains do not reach nomalus and do not send a pollen to it. Instead, Nucellus grows up, and contact with pollen grains is achieved. At Kedra, like fir, as a result of coordinated changes in the micropilene and nomegalus, pollen grains are in a naolelus, where they germinate.

Araucaria (Agathis and Araucaria), devoid of air bags, pollen grains germinate not on a seedness, but on seed scales or in her sinus. The pollen tube branches, and some of its branches are growing into the tissue of seed scales. They grow towards the seeds, reach the tops of the nicklice and penetrate it. Thus, the mechanism of pollination of the aracarium is characterized by a high specialization and is strongly deviated from the well-known forms of pollination of conifers.

Fertilization at coniferous, with the exception of pine, occurs shortly after pollination. At the species of pine between pollination and fertilization takes place from 12 to 14 months. Fertilization begins with the formation and growth of the pollen tube, which actively lays its way through the nicklick fabrics (macrosporangium) towards the Archegano. Approximately a week before the act of fertilization of the core of the spermatogenic cell is divided, forming two identical or unequal sizes (pine) men's machines. The tip of the pollen tube lays the path between the cervical cells of Archegononia and reaches the egg. Here it bursts, releasing men's gears in the cytoplasm of the egg. Following this, one of two men's weights enters the egg. The merger of two nuclei occurs very slowly, but in the end they are connected, forming the first core of the sporophyte.

2.5. The formation of the embryo seeds of coniferous

The development of the embryo seed in conifers begins with the formation of the prerepretation, or the infarded embryo (Project). The orembrio consists of a group of cells with a certain arrangement until the elongation of pendant or suspension cells. After that, the development of own embryo begins. The suspension not only push the germinal cells deep into the tissue of the GaMetophyte and serve for them to the Gaustorial organ, but are probably secretory bodies that destroy the Endosperma gamethophyt cell enzymes.

Soft seeds are very diverse in size and shape. Large seeds with roller coat, and the leather and webbed seeds of most conifers are equipped with one wingid appendage or two small wings, which contributes to their spread of the wind. Juicy bright cover on seeds of a row of conifers contributes to their distribution through animals.

Mature soft soft germ consists of a suspension, primary root, stalk and seedlings. Pendants in coniferous different lengths and shapes. At the cedar nut, it is strongly twisted and reaches a length of 1 cm. Semilyts are long, narrow and detect greater variability among even the same kind and type. Pine has the largest number of cotyledons and the greatest variability (from 3 to 18).

The reduced brief dendrological characteristic of conifers with the description of their philogenesis indicates that in the process of long-term evolution, a number of coniferous types have successfully adapted to changing environmental conditions by improving and consolidating in the progeny of ancient genetic structures that determine the manifestation of competitive signs and properties.

In confirmation of this situation, taiga forests can be given with the predominance of coniferous rocks, occupying huge areas of the cold zone in the northern hemisphere, forming stable clean and mixed coniferous-deciduous ancient.

Coromorphism of the assimilation apparatus, relative durability, the development of protective equipment (zhivitsa, essential oils), the structure of the water supply system, wind-source and a number of other features of the structure provided coniferous one of the leading provisions in the formation of modern forest formations on the globe.

Task 2. Structure of vegetative coniferous breeds

The purpose of the task is to study similar signs in the structure of the vegetative organs of coniferous plants.

Material for the lesson:
1) photographs and slides of the crown of crowns, shapes of the trunks and the nature of the peel of some representatives of the family of pine, taxi and cypressive; 2) Herbarian samples of ordinary pine escapes, spruce, the larch of the Siberian, Kedar of the Lebanese, sequoia evergreen and secoirendrid of giant, cypress and teu western; 3) samples of wood and bark of listed types of conifers; 4) The drugs of the microscopic structure of wood and bark. Equipment for class: Svityaz Diapricor, Polyluux Codoscope, Microscope, Preparation Magnical Magnifier, Drawing Apparatus, Preparation Needles (2-4), Napkin, Pencil, workbook And albums for drawing.

The procedure for performing the task:
1. Write out similar signs of the structure of the vegetative organs of coniferous breeds. Pay attention to the most characteristic of them: conifers of the first magnitude, more than 25-30 m, overlook the 1st dominant tier and are breeds of forest formers. In the mountainous conditions, they acquire shrub and stabular vital forms.

2. Pay attention to the monopodality of branching and the activity of Cambia, which form the secondary wood and the lob and ensures the formation of complete-dried column-shaped stems. Write out the size of some representatives of the family of pine, taxi and cypress and maximum duration of their lives. Trees - perennial plants forming a barrel on which the crown is formed, consisting of skeletal branches of 1 order, from which branches II, W, etc. are deposited, ending with shoots with leaves and kidneys. Barrel, branches, shoots, kidneys, leaves and roots make up the vegetative part of woody plants. Draw the structure of the structure of the tree with a pyramidal and punching crown; Recognize branches I, II, III, etc. orders and shoots.

3. Pay attention to the height of raising and the density of the crown, which are indicators of lightness and shadowability of species. Compare the cheva of the pine of the ordinary with the Tees Cheeva, sequoia evergreen, cypress and teu western.

Describe the general signs of the structure of the leaves of various orders and coniferous families. Draw anatomical pine needle elements, pay attention to resin strokes and vascular fibrous beams in the central needle cylinder. Tracheids conifers are performed by both water-conductive and mechanical functions.

4. The resin-free system and periderm protect wood from damage. Compare the structure of the bark and wood of some representatives of the coniferous subclass (Pine ordinary, Siberian fir, the secuualandron giant and thuja western). Pay attention to the structure of a normal and traumatic solid system of some conifers (pine, fir).

5. Submit the results by the material of the 2nd task. Pay attention to the competitive signs of coniferous in the structure of vegetative organs: the formation of large and durable trunks protected from pests by residuals and patient oils, the homogeneity of the structure of wood consisting of tracheid performing water-conductive and mechanical functions.

Task 3. The structure of the generative coniferous breeds

The purpose of the task is to consider the general signs of the structure of male and female strovers, seeds and microsposrans, as well as cones and seeds, which relate to the category of generative (reproductive) organs of coniferous plants.

Material for task: 1) Herbaric samples of shoots with male and female strobils and pine cones of ordinary, larch of the Siberian, Tui Western and Juniper ordinary; 2) drugs pollen pine, larch, spruce, juniper, teu, cypress; 3) fixed material during the flowering period of the pine of ordinary, larch of the Siberian, Tui of Western and Juniper ordinary; 4) Slides and photos for coniferous flowering.

Equipment for lesson: Preparation Magnifier, Svityaz Diaprosor, Polyluux Codoscope, Preparation Needles (2 - 4), Napkin, Pencil and Notebook (Album) for drawing.

Procedure for performing the task
1. Write out similar signs of the structure of the generative coniferous plants, which are laid at the end of the growing season preceding flowering (i.e., a year before flowering). The process of fertilization and ripening of seeds occurs per year of flowering, and some (pine, juniper) for the 2nd year after flowering. Therefore, woody plants are distinguished with a two-year-old reproductive cycle, which is calculated from the start of the generative (sex) organs to the ripening of seeds.

Conifers from women's gates (megastrobil) are developing cones, on the inside of the seed scales of which are formed "naked" seeds from fertilized seeds.

2. Spend comparison of the generative organs of some conifers ( planting material: tees berry, thuja western, pine ordinary, spruce european, larch Siberian et al.).

3. Please note that coniferous micro-tapes consist of microspophilles, which, as a rule, forms 2 microsphang (pollen bags). However, in some species of Araucaria and Agathis, the number of them reaches 13-15 pieces on each microspophyll. Pollen, or microspores, in coniferous dry, easily tolerated by the wind.

4. See preparations and sketch coniferous with air bags (pine, spruce) and without them (larch).

5. Get acquainted with megastrobyls (macroatrums) of two types of structure: The first type - Megastobils consist of well-developed seed scales with seeds, and crooks are weakly developed (pine, spruce); The second type - Megastorobils consist of a bent outward scales, painted often in a reddish-raspberry color, on the inside of which you can see small seed flakes with seedups (fir, larch, pseudotussuga).

6. Make comparative drawings, comparing the structure of Pine and larch megastrobil with cones formed from them.